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(11) | EP 1 427 697 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
SULPHONATION OF PHENOLS SULPHONIERUNG VON PHENOLEN SULFONATION DE PHENOLS |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] This invention relates to a novel and improved process for the preparation of sulphonated phenols.
[0002] Sulphonated phenols are widely used as dyes, medical intermediates, photo-developing chemicals and cosmetic preparations. In particular, 4-alkoxy-2-hydroxybenzophenone-5-sulphonic acids are suitable as UV absorbers in sun screening preparations.
[0003] It is known that phenols can be readily sulphonated with sulphuric acid, sulphur trioxide gas, dialkyl sulphuric acid and chlorosulphonic acid etc. The reaction is usually carried out in a solvent.
[0004] Solvents which have been used in the sulphonation of phenols include nitrobenzene, nitromethane, alkyl ethers, cyclic ethers, aliphatic hydrocarbons, chlorohydrocarbons and dialkyl carbonates, all of which present undesirable problems. For example, nitro solvents and alkyl ethers have a high risk of explosion and some cyclic ethers are extremely harmful and are not suited for the above mentioned uses of sulphonated phenols.
[0005] US Patent No 3468938 and US Patent No 3696077 disclose that 4-alkoxy-2 hydroxybenzophenones are reacted with chlorosulphonic acid in a chlorohydrocarbon solvent, e.g. 1,2 dichlorethane. However, this process has a number of disadvantages. For example, the toxicity of the stated solvents causes problems.
[0006] Japanese Patent Application Publication Number H9-227499 describes a method of sulphonating phenols using chlorosulphonic as sulphonating agent and dialkyl carbonates as solvent, e.g. dimethyl carbonate, diethyl carbonate and di-isopropyl carbonate. French Patent Application Number 2791057 also describes the use of dialkyl carbonates as a solvent in the preparation of 4-alkoxy-2-hydroxybenophenone-5-sulphonic acids. Aryl sulphonic acids are, however, thermally unstable when dissolved in hot dialkyl carbonates leading to degradation, loss of yield and contamination of the product. Moreover, French Patent Application Number 2791057 also states that the use of aliphatic hydrocarbons of 5-8 carbon atoms cause problems of colouration and the formation of by-products which affect the purity of the final product.
[0007] US Patent Number 5072034 describes a method of preparing-4-alkoxy-2-hydroxybenzophenone-5-sulphonic acids by reacting a 4-alkoxy-2-hydroxybenzophenone with chlorosulphonic acid wherein the reaction is carried out in carboxylic ester solvents, e.g. ethyl acetate. These are not satisfactory solvents because degradation leads to the formation of carboxylic acids which impart undesirable odour to the product.
[0008] It is an object of the present invention to provide a novel and improved process for the preparation of sulphonated phenols which overcomes the disadvantages of the known processes.
[0009] According to the present invention there is provided a process for the preparation of sulphonated phenols of the general formula I
where R1 is hydrogen, a C1-C20 alkyl group which is unsubstituted or substituted by halogen, cyano, hydroxyl, C1-C20 alkoxy, C2-C20 alkoxycarbonyl, acyloxy and/or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, R2 is hydrogen, C1-C20 alkyl or benzoyl of the general formula II
where R3 and R4 independently of one another are each hydrogen, halogen, C1-C12 alkyl, C1-C12 alkoxy, C1-C4 haloalkyl, C3-C8 cycloalkyl, C4-C12 cycloalkylalkyl, cyano, hydroxyl, or hydroxyethyl or are each phenoxy, C7-C10 phenylalkyl or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, and R5 is hydrogen or the group SO3X where X can be hydrogen, a monovalent metal or a group-N(R6)3, where each of the radicals R6 can be independently of one another hydrogen C1-C6 alkyl or C1-C6 hydroxy alkyl, which process comprises reacting a phenol of the general formula III
where R1 and R2 are as defined above, with a halosulphonic acid in a solvent which is a mixture of a C5-C10 aliphatic or cycloaliphatic hydrocarbon and a dialkyl carbonate of the general formula IV
R7-O-CO-O-R8 IV
where R7 and R8 each represent independently a C1-C4 alkyl group.
[0010] The phenol of the general formula III preferably is catechol, resorcinol, hydroquinone or a benzophenone.
[0013] Preferably, the dialkyl carbonate in the solvent mixture is dimethyl carbonate, diethyl carbonate or di-isopropyl carbonate.
[0014] Further preferably, the aliphatic or cycloaliphatic hydrocarbon in the solvent mixture is hexane, cyclohexane, methylcyclohexane, heptane, isooctane, isononane or decane.
[0015] The process of the invention conveniently is carried out with an excess of the phenol of general formula III over the halosulphonic acid, preferably an excess of 2 to 5 mol % of the phenol.
[0016] The process of the invention furthermore is conveniently carried out with the concentration of phenol of the general formula III in the solvent mixture being 5 to 50% w/w, preferably 15 to 30% w/w.
[0017] The dialkyl carbonate solvent and the aliphatic or cycloaliphatic hydrocarbon solvent are mixed in a weight ratio of from 10:90 to 90:10, preferably 40:60 to 60:40.
[0018] Preferably, the process of the invention is carried out at a temperature between -10°C to 80°C.
[0019] Conveniently the sulphonation reaction is carried out at a temperature between 0°C to 30°C and the products from the sulphonation are then raised gradually to 60°C to 70°C to remove acid product from the sulphonation reaction.
[0020] Further preferably, the sulphonation reaction is carried out under a pressure between 2mm and 760mm.
[0021] A particular advantage of using a mixed dialkyl carbonate/aliphatic or cycloaliphatic hydrocarbon solvent according to the invention is that it allows reflux at lower temperatures to facilitate removal of biproduct acid (e.g. HCl) from the sulphonation reactor. A further advantage is that the mixed solvent acts to reduce the solubility of the sulphonated product in the solvent thereby facilitating easy recovery of the product and higher yield of the product. An additional very important benefit of the use of the mixed solvent system is the avoidance of problems of colour and impurities that are observed when an aliphatic hydrocarbon solvent is used on its own.
[0022] Aryl sulphonates are generally not very stable (with regard to desulphonation) when dissolved in, for example, dialkyl carbonate solvents. By carrying out the reaction in the mixed solvent, this leads to reduced degradation due to lower temperatures and precipitation of the product.
[0023] In the sulphonation of 4-alkoxy-2-hydroxy benzophenones by the process according to the invention, a sulphonic acid group is, as a rule, introduced into the 4-alkoxy-2-hydroxy nucleus of the starting compound. If the reactivity of the second nucleus has been increased by appropriate substitution with electron donor groups, such as hydroxyl or alkoxy, it is also possible introduce two sulpho radicals. For example, the reaction of 2,2'-dihydroxy-4,4'-dimethoxybenzophenone with two moles of sulphonating agent gives 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulphonic acid.
[0024] With regard to the use of 4-alkoxy-2-hydroxybenzophenone-5-sulphonic acids as UV absorbers, particularly preferred radicals are those in which R1 is C1-C18-alkyl, R3 is in the ortho-position to the ketonic carbonyl group and is hydrogen or hydroxyl and R5 is hydrogen. Other important compounds are those in which R1 is C1-C18-alkyl, R3 and/or R4 are each hydrogen or R3 is an ortho-hydroxyl group and R4 is a para-alkoxy group, and R5 is hydrogen.
[0025] Regarding their use as UV absorbers, particularly suitable compounds are the following:
2-hydroxy-4-methoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-ethoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-propoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-isopropoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-butoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-isobutoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-sec-butoxybenzophenone-5-sulphonic acid,
2-hydroxy4-n-pentyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-hexyloxybenzophenone-5-sulphonic acid,
2-hydroxy4-isohexyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-heptyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-isoheptyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-octyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-(3,4-dimethyl-1-hexyloxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-(3,5-dimethyl-1-hexyloxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-(4,5-dimethyl-1-hexyloxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-(3-methyl-1-heptyloxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-n-nonyloxybenzophenone-5-sulphonic acid,
2-hydroxy-n-decyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-undecyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-dodecyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-hexadecyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-n-octadecyloxybenzophenone-5-sulphonic acid,
2-hydroxy-4-(2-acetoxyethoxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-(2-phenbenzoyloxyethoxy)-benzophenone-5-sulphonic acid,
2-hydroxy-4-phenylmethyleneoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-(2-phenylethyleneoxy)-benzophenone-5-sulphonic acid,
2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulphonic acid,
2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-sulphonic acid,
2,2'-dihydroxy-4-methoxybenzophenone-5-sulphonic acid,
2-hydroxy-4'-fluoro-4-methoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-methoxy-4'-methylbenzophenone-5-sulphonic acid,
2-hydroxy-4-methoxy-4'-phenoxybenzophenone-5-sulphonic acid,
2-hydroxy-4-methoxy-4'-chlorobenzophenone-5-sulphonic acid,
2-hydroxy-4-methoxycarbonylmethyleneoxybenzophenone-5-sulphonic acid and
2-hydroxy-4-ethoxycarbonylmethyleneoxybenzophenone-5-sulphonic acid.
Examples of the Invention
Example 1: Preparation of 2-Hydroxy-4-methoxybenzophenone-5-sulphonic Acid
[0026] 145g (0.634 moles) of 2-hydroxy-4-methoxybenzophenone, 480g dimethyl carbonate and 320 g cyclohexane were charged under nitrogen to a 4-necked one litre reactor fitted with stirrer, thermometer and condenser attached to an HCl scrubber system. The reaction mixture was heated to 60°C and 70.4g (0.604 moles) of chlorosulphonic acid added over a period of 4h with removal of hydrogen chloride gas. On completion of the addition, the reaction mixture is heated to 70-72°C for 1h, and then cooled to 20°C. The product was collected by filtration and washed with dimethyl carbonate/cyclohexane (2 x 60g/40g) and dried under reduced pressure at 50°C to give 167.5g (90%) of 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid.
Example 2: Preparation of 2-Hydroxy-4-methoxybenzophenone-5-sulphonic Acid
[0027] Example 1 was repeated except diethyl carbonate (480g) was used instead of dimethyl carbonate yielding 158g (85%) of 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid.
Example 3: Preparation of 2-Hydroxy-4-methoxybenzophenone-5-sulphonic Acid
[0028] Example 1 was repeated except heptane (320g) was used instead of cyclohexane yielding 152g (82%) of 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid.
Example 4: Preparation of 2,4-Dihydroxybenzene sulphonic Acid
[0029] 15.0g (0.136 moles) of resorcinol, 102g dimethyl carbonate and 68g cyclohexane were charged under nitrogen to a 4-necked one litre reactor fitted with stirrer, thermometer and condenser attached to an HCl scrubber system. The reaction mixture was heated to 60°C and 15.1g (0.13 moles) of chlorosulphonic acid added over a period of 4h with removal of hydrogen chloride gas. On completion of the addition, the reaction mixture is heated to 70-72°C for 1h, and then cooled to 20°C. The reaction mixture separated into two layers with the lower layer containing 2,4-dihydroxybenzene sulphonic Acid (63.2% by hplc) and resorcinol (31.5% by hplc).
Example 5: Preparation of 1,4-Di-hydroxybenzene sulphonic Acid
[0030] 15.0g (0.136 moles) of hydroquinone, 102g dimethyl carbonate and 68g cyclohexane were charged under nitrogen to a 4-necked one litre reactor fitted with stirrer, thermometer and condenser attached to an HCl scrubber system. The reaction mixture was heated to 60°C and 15.1g (0.13 moles) of chlorosulphonic acid added over a period of 4h with removal of hydrogen chloride gas. On completion of the addition, the reaction mixture is heated to 70-72°C for 1h, and then cooled to 20°C. The reaction mixture separated into two layers with the lower layer containing 1,4-dihydroxybenzene sulphonic acid (60% by hplc) and hydroquinone (38% by hplc).
Example 6: Preparation of 2,4-Di-hydroxy-benzophenone-5-sulphonic Acid
[0031] 29.0g (0.136 moles) of 2,4-dihydroxybenzophenone, 102g dimethyl carbonate and 68g cyclohexane were charged under nitrogen to a 4-necked one litre reactor fitted with stirrer, thermometer and condenser attached to an HCl scrubber system. The reaction mixture was heated to 60°C and 15.1g (0.13 moles) of chlorosulphonic acid added over a period of 4h with removal of hydrogen chloride gas. On completion of the addition, the reaction mixture is heated to 70-72°C for 1h, and then cooled to 20°C. The reaction mixture separated into two layers with the lower layer containing 2,4-dihydroxy-benzophenone-5-sulphonic acid (94.8% by hplc) and 2,4-dihydroxybenzophenone (3.4% by hplc).
Example 7: Preparation of 2-Hydroxy-4-methoxybenzophenone-5-sulphonic Acid
[0032] 42.4g (0.13 moles) of 2-hydroxy-4-octyloxybenzophenone, 102g dimethyl carbonate and 68 g cyclohexane were charged under nitrogen to a 4-necked one litre reactor fitted with stirrer, thermometer and condenser attached to an HCl scrubber system. The reaction mixture was heated to 60°C and 15.1g (0.13 moles) of chlorosulphonic acid added over a period of 2h with removal of hydrogen chloride gas. On completion of the addition, the reaction mixture is heated to 70-72°C for 1h, and then cooled to 20°C. The product was collected by filtration and washed with dimethyl carbonate/cyclohexane (52/34g) and dried under reduced pressure at 50°C to give 5.8g of 2-hydroxy-4-octyloxybenzophenone-5-sulphonic acid, and a mother liquor (256g) containing 2-hydroxy-4-octyloxybenzophenone-5-sulphonic acid (82.4% by hplc) and 2-hydroxy-4-octyloxybenzophenone (16% by hplc).
Examples 8-13
[0033] The following table describes the effect of different ratios of dimethyl carbonate (DMC) and cyclohexane on the recovered yield of 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid.
Experimental conditions were as described in Example 1.
| Example | DMC (%) | Cyclohexane (%) | Yield (%) |
| 1 | 60 | 40 | 90 |
| 8 | 100 | 0 | 73 |
| 9 | 0 | 100 | Note 1 |
| 10 | 10 | 90 | Note 1 |
| 11 | 60 | 40 | 92 (Note 2) |
| 12 | 50 | 50 | 88 |
| 13 | 40 | 60 | 90 |
| Note 1: The product was coloured and very sticky - not isolatable. Note 2: Repeat of Example 1 |
1. A process for the preparation of sulphonated phenols of the general formula I
where R1 is hydrogen, a C1-C20 alkyl group which is unsubstituted or substituted by halogen, cyano, hydroxyl, C1-C20 alkoxy, C2-C20 alkoxycarbonyl, acyloxy and/or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, R2 is hydrogen, C1-C20 alkyl or benzoyl of the general formula II
where R3 and R4 independently of one another are each hydrogen, halogen, C1-C12 alkyl, C1-C12 alkoxy, C1-C4 haloalkyl, C3-C8 cycloalkyl, C4-C12 cycloalkylalkyl, cyano, hydroxyl, or hydroxyethyl or are each phenoxy, C7-C10 phenylalkyl or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, and R5 is hydrogen or the group SO3 X where X can be hydrogen, a monovalent metal or a group -N(R6)3, where each of the three radicals R6 can be independently of one another hydrogen, C1-C6 alkyl or C1-C6 hydroxy alkyl which process comprises reacting a phenol of the general formula III
where R1 and R2 are as defined above, with a halosulphonic acid in a solvent which is a mixture of a C5-C10 aliphatic or cycloaliphatic hydrocarbon and a dialkyl carbonate of the general formula IV
R7-O-CO-O-R8 IV
where R7 and R8 each represent independently a C1-C4 alkyl group.
where R1 is hydrogen, a C1-C20 alkyl group which is unsubstituted or substituted by halogen, cyano, hydroxyl, C1-C20 alkoxy, C2-C20 alkoxycarbonyl, acyloxy and/or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, R2 is hydrogen, C1-C20 alkyl or benzoyl of the general formula II
where R3 and R4 independently of one another are each hydrogen, halogen, C1-C12 alkyl, C1-C12 alkoxy, C1-C4 haloalkyl, C3-C8 cycloalkyl, C4-C12 cycloalkylalkyl, cyano, hydroxyl, or hydroxyethyl or are each phenoxy, C7-C10 phenylalkyl or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, and R5 is hydrogen or the group SO3 X where X can be hydrogen, a monovalent metal or a group -N(R6)3, where each of the three radicals R6 can be independently of one another hydrogen, C1-C6 alkyl or C1-C6 hydroxy alkyl which process comprises reacting a phenol of the general formula III
where R1 and R2 are as defined above, with a halosulphonic acid in a solvent which is a mixture of a C5-C10 aliphatic or cycloaliphatic hydrocarbon and a dialkyl carbonate of the general formula IV
R7-O-CO-O-R8 IV
where R7 and R8 each represent independently a C1-C4 alkyl group.
2. A process as claimed in claim 1 wherein the phenol of general formula III is catechol,
resorcinol, hydroquinone or a benzophenone.
3. A process as claimed in claim 2 wherein the benzophenone is a 4-alkoxy-2-hydroxybenzophenone.
4. A process as claimed in any one of claims 1 to 3 wherein the halosulphonic acid is
chlorosulphonic acid.
5. A process as claimed in any one of the preceding claims wherein the dialkyl carbonate
in the solvent mixture is dimethyl carbonate, diethyl carbonate or di-isopropyl carbonate.
6. A process as claimed in any one of the preceding claims wherein the aliphatic or cycloaliphatic
hydrocarbon in the solvent mixture is hexane, cyclohexane, methylcyclohexane, heptane,
isooctane, isononane or decane.
7. A process as claimed in any one of the preceding claims carried out with an excess
of the phenol of general formula III over the halosulphonic acid.
8. A process as claimed in claim 7 carried out with a 2 to 5 mol% excess of the phenol
over the halosulphonic acid.
9. A process as claimed in any one of the preceding claims wherein the concentration
of the phenol of general formula III in the solvent mixture is 5 to 50% w/w.
10. A process as claimed in claim 9 wherein the concentration of the phenol in the solvent
mixture is 15 to 30% w/w.
11. A process as claimed in any one of the preceding claims wherein the dialkyl carbonate
solvent and the aliphatic or cycloaliphatic hydrocarbon solvent are mixed in a weight
ratio of from 10:90 to 90:10.
12. A process as claimed in claim 11 wherein the weight ratio of the dialkyl carbonate
solvent to the aliphatic or cycloaliphatic hydrocarbon solvent is 40:60 to 60:40.
13. A process as claimed in any one of the preceding claims carried out a temperature
between -10°C and 80°C.
14. A process as claimed in claim 13 wherein the sulphonation reaction is carried out
at a temperature between 0°C to 30°C and the products of the sulphonation are then
raised gradually to 60°C to 70°C to remove acid biproduct from the sulphonation reaction.
15. A process as claimed in any one of the preceding claims carried out at a pressure
between 2mm and 760mm.
1. Verfahren zur Herstellung sulfonierter Phenole der allgemeinen Formel I
worin R1 für Wasserstoff, eine C1-C20-Alkylgruppe, die unsubstituiert oder substituiert ist mit Halogen, Cyano, Hydroxyl, C1-C20-Alkoxy, C2-C20-Alkoxycarbonyl, Acyloxy und/oder Phenyl, das unsubstituiert oder substituiert ist mit C1-C4-Alkyl, C1-C4-Alkoxy und/oder Halogen, und R2 für Wasserstoff, C1-C20-Alkyl oder Benzoyl der allgemeinen Formel II steht
worin R3 und R4 unabhängig voneinander jeweils für Wasserstoff, Halogen, C1-C12-Alkyl, C1-C12-Alkoxy, C1-C4-Halogenalkyl, C3-C8-Cycloalkyl, C4-C12-Cycloalkylalkyl, Cyano, Hydroxyl oder Hydroxyethyl stehen oder jeweils für Phenoxy, C7-C10-Phenylalkyl oder Phenyl stehen, das unsubstituiert oder substituiert ist mit C1-C4-Alkyl, C1-C4-Alkoxy und/oder Halogen, und R5 für Wasserstoff oder die Gruppe SO3X steht, worin X für Wasserstoff, ein monovalentes Metall oder eine Gruppe -N(R6)3 stehen kann, worin jeder der drei Reste R6 unabhängig voneinander für Wasserstoff, C1-C6-Alkyl oder C1-C6-Hydroxyalkyl stehen kann, durch Umsetzung eines Phenols der allgemeinen Formel III
worin R1 und R2 wie oben definiert sind, mit einer Halogensulfonsäure in einem Lösemittel, das ein Gemisch eines C5-C10-aliphatischen oder cycloaliphatischen Kohlenwasserstoffs ist, mit einem Dialkylcarbonat der allgemeinen Formel IV
R7-O-CO-O-R8 IV
worin R7 und R8 jeweils unabhängig für eine C1-C4-Alkylgruppe stehen.
worin R1 für Wasserstoff, eine C1-C20-Alkylgruppe, die unsubstituiert oder substituiert ist mit Halogen, Cyano, Hydroxyl, C1-C20-Alkoxy, C2-C20-Alkoxycarbonyl, Acyloxy und/oder Phenyl, das unsubstituiert oder substituiert ist mit C1-C4-Alkyl, C1-C4-Alkoxy und/oder Halogen, und R2 für Wasserstoff, C1-C20-Alkyl oder Benzoyl der allgemeinen Formel II steht
worin R3 und R4 unabhängig voneinander jeweils für Wasserstoff, Halogen, C1-C12-Alkyl, C1-C12-Alkoxy, C1-C4-Halogenalkyl, C3-C8-Cycloalkyl, C4-C12-Cycloalkylalkyl, Cyano, Hydroxyl oder Hydroxyethyl stehen oder jeweils für Phenoxy, C7-C10-Phenylalkyl oder Phenyl stehen, das unsubstituiert oder substituiert ist mit C1-C4-Alkyl, C1-C4-Alkoxy und/oder Halogen, und R5 für Wasserstoff oder die Gruppe SO3X steht, worin X für Wasserstoff, ein monovalentes Metall oder eine Gruppe -N(R6)3 stehen kann, worin jeder der drei Reste R6 unabhängig voneinander für Wasserstoff, C1-C6-Alkyl oder C1-C6-Hydroxyalkyl stehen kann, durch Umsetzung eines Phenols der allgemeinen Formel III
worin R1 und R2 wie oben definiert sind, mit einer Halogensulfonsäure in einem Lösemittel, das ein Gemisch eines C5-C10-aliphatischen oder cycloaliphatischen Kohlenwasserstoffs ist, mit einem Dialkylcarbonat der allgemeinen Formel IV
R7-O-CO-O-R8 IV
worin R7 und R8 jeweils unabhängig für eine C1-C4-Alkylgruppe stehen.
2. Verfahren nach Anspruch 1, worin das Phenol der allgemeinen Formel III Catechol, Resorcinol,
Hydrochinon oder ein Benzophenon ist.
3. Verfahren nach Anspruch 2, worin das Benzophenon ein 4-Alkoxy-2-hydroxybenzophenon
ist.
4. Verfahren nach einem der Ansprüche 1 bis 3, worin die Halogensulfonsäure Chlorsulfonsäure
ist.
5. Verfahren nach einem der vorhergehenden Ansprüche, worin das Dialkylcarbonat in dem
Lösemittelgemisch Dimethylcarbonat, Diethylcarbonat oder Diisopropylcarbonat ist.
6. Verfahren nach einem der vorhergehenden Ansprüche, worin der aliphatische oder cycloaliphatische
Kohlenwasserstoff in dem Lösemittelgemisch Hexan, Cyclohexan, Methylcyclohexan, Heptan,
Isooctan, Isononan oder Decan ist.
7. Verfahren nach einem der vorhergehenden Ansprüche, das durchgeführt wird mit einem
Überschuss des Phenols der allgemeinen Formel III gegenüber der Halogensulfonsäure.
8. Verfahren nach Anspruch 7, das durchgeführt wird mit einem 2 bis 5 Mol %igen Überschuss
des Phenols gegenüber der Halogensulfonsäure.
9. Verfahren nach einem der vorhergehenden Ansprüche, worin die Konzentration des Phenols
der allgemeinen Formel III in dem Lösemittelgemisch 5 bis 50 % Gew./Gew. beträgt.
10. Verfahren nach Anspruch 9, worin die Konzentration des Phenols in dem Lösemittelgemisch
15 bis 30 % Gew./Gew. beträgt.
11. Verfahren nach einem der vorhergehenden Ansprüche, worin das Dialkylcarbonatlösemittel
und das aliphatische oder cycloaliphatische Kohlenwasserstofflösemittel in einem Gewichtsverhältnis
von 10:90 bis 90:10 gemischt werden.
12. Verfahren nach Anspruch 11, worin das Gewichtsverhältnis des Dialkylcarbonatlösemittels
zum aliphatischen oder cycloaliphatischen Kohlenwasserstofflösemittel 40:60 bis 60:40
beträgt.
13. Verfahren nach einem der vorhergehenden Ansprüche, das bei einer Temperatur zwischen
-10°C und 80°C durchgeführt wird.
14. Verfahren nach Anspruch 13, worin die Sulfonierungsreaktion bei einer Temperatur zwischen
0°C und 30°C durchgeführt wird und die Produkte der Sulfonierung dann allmählich auf
60°C bis 70°C angehoben werden, um das Säurebiprodukt aus der Sulfonierungsreaktion
zu entfernen.
15. Verfahren nach einem der vorhergehenden Ansprüche, das bei einem Druck zwischen 2
mm und 760 mm durchgeführt wird.
1. Procédé de préparation de phénols sulfonés de la formule générale I :
dans laquelle R1 représente : hydrogène, groupement alkyle en C1-C20, non substitué ou substitué par halogène, cyano, hydroxyle, alkoxy en C1-C20, alkoxycarbonyle en C2-C20, acyloxy et/ou phényle non substitué ou substitué par alkyle en C1-C4, alkoxy en C1-C4 et/ou halogène, R2 représente : hydrogène, alkyle en C1-C20 ou benzoyle de la formule générale II :
dans laquelle R3 et R4 représentent indépendamment l'un de l'autre : hydrogène, halogène, alkyle en C1-C12, alkoxy en C1-C12, haloalkyle en C1-C4, cycloalkyle en C3-C8, cycloalkylalkyle en C4-C12, cyano, hydroxyle, ou hydroxyéthyle, ou représentent chacun phénoxy, phénylakyle en C7-C10 ou phényle non substitué ou substitué par alkyle en C1-C4, alkoxy en C1-C4 et/ou halogène, et R5 représente l'hydrogène ou le groupement SO3X, où X peut représenter : hydrogène, métal monovalent ou groupement -N(R6)3, où chacun des trois radicaux R6 peut représenter indépendamment : hydrogène, alkyle en C1-C6 ou hydroxyalkyle en C1-C6, lequel procédé comprend la réaction d'un phénol de la formule générale III
dans laquelle R1 et R2 sont tels que définis plus haut, avec un acide halosulfonique dans un solvant qui est un mélange d'un hydrocarbure aliphatique ou cycloaliphatique en C5-C10 et d'un carbonate de dialkyle de la formule générale IV
R7-O-CO-O-R8 IV
dans laquelle R7 et R8 représentent chacun indépendamment un groupement alkyle en C1-C4.
dans laquelle R1 représente : hydrogène, groupement alkyle en C1-C20, non substitué ou substitué par halogène, cyano, hydroxyle, alkoxy en C1-C20, alkoxycarbonyle en C2-C20, acyloxy et/ou phényle non substitué ou substitué par alkyle en C1-C4, alkoxy en C1-C4 et/ou halogène, R2 représente : hydrogène, alkyle en C1-C20 ou benzoyle de la formule générale II :
dans laquelle R3 et R4 représentent indépendamment l'un de l'autre : hydrogène, halogène, alkyle en C1-C12, alkoxy en C1-C12, haloalkyle en C1-C4, cycloalkyle en C3-C8, cycloalkylalkyle en C4-C12, cyano, hydroxyle, ou hydroxyéthyle, ou représentent chacun phénoxy, phénylakyle en C7-C10 ou phényle non substitué ou substitué par alkyle en C1-C4, alkoxy en C1-C4 et/ou halogène, et R5 représente l'hydrogène ou le groupement SO3X, où X peut représenter : hydrogène, métal monovalent ou groupement -N(R6)3, où chacun des trois radicaux R6 peut représenter indépendamment : hydrogène, alkyle en C1-C6 ou hydroxyalkyle en C1-C6, lequel procédé comprend la réaction d'un phénol de la formule générale III
dans laquelle R1 et R2 sont tels que définis plus haut, avec un acide halosulfonique dans un solvant qui est un mélange d'un hydrocarbure aliphatique ou cycloaliphatique en C5-C10 et d'un carbonate de dialkyle de la formule générale IV
R7-O-CO-O-R8 IV
dans laquelle R7 et R8 représentent chacun indépendamment un groupement alkyle en C1-C4.
2. Procédé selon la revendication 1, dans lequel le phénol de formule générale III est
le catéchol, le résorcinol, l'hydroquinone ou une benzophénone.
3. Procédé selon la revendication 2, dans lequel la benzophénone est une 4-alkoxy-2-hydroxybenzophénone.
4. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel l'acide halosulfonique
est l'acide chlorosulfonique.
5. Procédé selon l'une quelconque des revendications précédentes, dans lequel le carbonate
de dialkyle dans le mélange solvant est le carbonate de diméthyle, le carbonate de
diéthyle ou le carbonate de diisopropyle.
6. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'hydrocarbure
aliphatique ou cycloaliphatique dans le mélange solvant est : hexane, cyclohexane,
méthylcyclohexane, heptane, isooctane, isononane ou décane.
7. Procédé selon l'une quelconque des revendications précédentes, mis en oeuvre avec
un excès du phénol de formule générale III par rapport à l'acide halosulfonique.
8. Procédé selon la revendication 7, mis en oeuvre avec un excès 2 à 5 % molaires du
phénol par rapport à l'acide halosulfonique.
9. Procédé selon l'une quelconque des revendications précédentes, dans lequel la concentration
du phénol de la formule générale III dans le mélange solvant est de 5 à 50 masse/masse.
10. Procédé selon la revendication 9, dans lequel la concentration du phénol dans le mélange
solvant est de 15 à 30 masse/masse.
11. Procédé selon l'une quelconque des revendications précédentes, dans lequel le solvant
carbonate de dialkyle et le solvant hydrocarbure aliphatique ou cycloaliphatique sont
mélangés dans un rapport en masse de 10:90 à 90:10.
12. Procédé selon la revendication 11, dans lequel le rapport en masse du solvant carbonate
de dialkyle par rapport au solvant hydrocarbure aliphatique ou cycloaliphatique est
de 40:60 à 60:40.
13. Procédé selon l'une quelconque des revendications précédentes, mis en oeuvre à une
température entre -10 °C et 80 °C.
14. Procédé selon la revendication 13, dans lequel la réaction de sulfonation est mise
en oeuvre à une température entre 0 °C et 30 °C, et les produits de la sulfonation
sont ensuite amenés progressivement à 60 °C à 70 °C pour éliminer un sous-produit
acide de la réaction de sulfonation.
15. Procédé selon l'une quelconque des revendications précédentes, mis en oeuvre à une
pression entre 2 mm et 760 mm.
REFERENCES CITED IN THE DESCRIPTION
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Patent documents cited in the description